.left{
    float: left;
}
button{
    position: fixed;
    top: 50%;
    right: 0;
    display: block;/*按钮显示*/
}
@media screen and (min-width:1366px){
    
.panel_1{
    width:30%;
    height: 100%;
    background-color:gray;
    display:inline-block;
    top:3em;
}
button{
    display:none;/*按钮不显示显示*/
}

}
